Recently, with advance of fine processing technologies as represented by very-large-scale integrated circuits, trace amounts of impurities which remain on substrates (metal ions, and particles of inorganic materials such as metals and organic materials such as resist resins) have a large influence on performances or yield of devices, therefore the control of impurities has become quite important. In particular, since the particle itself to be cleaned off, becomes more easily adhered on interfaces by further pulverization of particles, establishment of an advanced cleaning technology is now in urgent need.
For this reason, conventionally, for preventing this contamination by particles, a method of reducing adhesion of particles by adding a surfactant to lower the zeta potential on the particle surface has been proposed (Japanese Kokai Publication Hei-05-138142 and Japanese Kokai Publication Hei-06-41770).
However, since the surfactant proposed in Japanese Kokai Publication Hei-05-138142 is a nonionic surfactant, the zeta potential on the particle surface cannot be sufficiently lowered, and the readhesion prevention ability thereof is insufficient. Moreover, the surfactant proposed in Japanese Kokai Publication Hei-06-41770 is an anionic surfactant, and can improve the readhesion prevention effect to some extent by lowering the zeta potential on the particle surface for sure, but is insufficient in view of the performance. Furthermore, an alkali metal such as sodium ion is used as a counter ion of the anionic surfactant, and thus there were serious problems for causing reliability decrease of devices due to latent flaw or damage of yellowing on the substrate surface caused by alkali metals remaining after cleaning and/or due to diffusion of the alkali metals into the substrate inside, being incapable of using due to heavy foaming at the time of using, or the like.